Magnetic ski bindings



Dec 12, 1967 i K. P. ROSENBERG 3,357,712

MAGNETIC SKI BINDINGS Filed Dec. 1, 1965 3 Sheets-Sheet 1 INI/ENTOR KENNETH R ROSENBERG ATTORNEY Dec. 12, 1967 K- P. ROSENBERG 3,357,712

MAGNETIC SKI BINDINGS Filed Dec. 1, 1965 3 Sheets-Sheet 2 7g 52 r 70 47 1 a 39- 86 7? m-g IN I/E/V TOR KENNETH F. ROSENBERG ATTORME rs Dec. 12, 1967 K. P. ROSENBERG MAGNETIC SKI BINDINGS Filed Dec. 1, 1965 5 Sheets-Sheet INVENTOR KENNETH P. ROSENBERG A TTORNEYS United States Patent Office 3,357,712 MAGNETIC SKI BINDINGS Kenneth P. Rosenberg, 1301 Grant Ave., Novato, Calif. 94947 Filed Dec. 1, 1965, Ser. No. 510,917

19 Claims. (Cl. 280-1135) This is a continuation-in-part application of my copending application Ser. No. 428,124 for Magnetic Ski Bindings.

The present invention relates to ski bindings and more particularly to safety ski bindings employing magnetic latching means.

The ideal ski binding is one which secures a skiers boot to his ski in a manner which prevents all relative movement therebetween until the skier falls, at which time the binding completely release the boot from'the ski. For downhill skiing purposes it isessential for the skiers boot to be securely held to the ski so that the ski and boot are integral. Only in this way can the skier effectively apply his weight to the ski for controlling his direction of travel. When a binding fails to firmly secure a boot to a ski and allows relative movement between the boot and the ski, such as heel lift, the skiers ability to control his skis is impaired and the binding fails to perform a vital function. It is not uncommon for expert skiers to strap their boots directly onto their skis to absolutely prevent relative motion between the ski and the boot. In doing so, however, they completely abandon the safety feature of a ski binding which releases the-boot when the skier falls.

The Wide variety of available ski bindings which are sold and used by skiers throughout the world evidences the fact that no single safety ski binding now known in the art functions in the ideal manner described above.

Most safety ski bindings include several hinged members and at least one spring member. These bindings allow heel lift, and are subject to malfunction due to the introduction of snow and ice during operation. Ski bin-dings of this general description are not easily operated under any conditions and are often extremely difiicult to operate in the adverse conditions which exist on the slopes of a mountain. Thus a fallen skier who tries to re-secure his boots to his skis while on a slope is often confronted with a frustrating task.

Some ski bindings require special brackets and plates to be secured to the skiers boots, which prevent the skier from using those boots with any other type of ski binding. Other ski bindings not only require modification to the boot but also place unusual forces on the boot and thus greatly reduce the life of the boot.

The present invention teachesa ski binding which securely holds the skiers boot to the ski, releases the boot when the skier falls, regardless of the direction of the fall, is easily operated, does not include complicated parts subject to malfunction, does not require modification of the skiers boot or place unusual strains on the boot, is long lasting and able to operate with all standard ski boots.

Further, the present invention teaches a ski binding employing a magnetic latching means. i

In one embodiment of the present invention the skiers boot is secured to the face of the ski by means of a binding cable which grasps the heel of the skiers boot and forces it down onto the ski. A magnetic latching mechanism is connected "to the cable and supplies the holding force. The latching mechanism is designed to supply a holding force which is variable to accommodate the varying needs of skiers of different weight and skiing capabilities while the cable makes it possible for the binding to accommodate all standard skiboots. Themagnetic latching mechanism is designed to have a minimum numher of moving parts and be unaffected by the presence of ice or snow. The latching mechanism also operates without any springs which suffer relatively large parameter changes in response to varying temperature conditions which skiers encounter during skiing. Thus, when the binding as taught by the present invention is adjusted to provide a certain holding force, this force will remain essentially constant over a wide temperature range. The elimination of a spring as the main holding force means also eliminates heel lift which is characteristic of spring actuated safety bindings. The absence of heel movement is a result of the inverse square law under which the magnet operates: the magnetic attraction varies inversely as the square of the distance increases from the poles.

A second embodiment of the present invention operates to secure a skiers boot to a ski through a lever mechanism which operates directly on the heel of the ski. This type of binding is commonly referred to as a step-in bin-ding as opposed to the cable binding referred to above. One of the outstanding features of the present invention is the ability to use the same magnetic latching mechanism with both the cable binding embodiment and the step-in binding embodiment. By virtue of this feature, a skier is able to convert from one type of binding to another without the expense of acquiring a completely different binding. The cost of the-parts which'enable a binding of the present invention to be converted froma cable binding to a step-in binding, or vice versa, is a small fraction of the cost of the complete binding itself.

The present invention also teaches the use of a magnetic toe locator which is exceptionally advantageous when re-binding skis while on a slope.

' Accordingly, it is an object of the present invention to provide an improved safety ski binding having all of the features desired of a ski binding A further object of the present invention is to provide a ski binding which secures the skiers boot to a ski in a manner which prevents relative movement therebetween but releases the boot completely when a force is applied to the binding which indicates that the skier is falling.

Further objects of the present invention include the provision of a ski binding which is simple in construction and not subject to malfunction due to the introduction of ice and snow, a ski bin-ding which releases in response to the application of a force greater than a preselected force regardless of the direction in which that force is applied, a magnetic latching means which eliminates the use of springs and a magnetic toe locator of anovel design.

Yet another object of the present invention is to provide a ski binding mechanism which is readily convertible from a cable binding to a step in binding, and vice versar Further objects and advantages of the present invention will be made apparent in the following specification wherein a preferred form of the invention is described by reference to the accompanying drawings.

In the drawings:

FIG. 1 is an isometric illustrationof the cable binding embodiment of the ski binding of the present invention, shown together with a boot;

FIG. 2 is a plan view of the binding and boot of FIG. 1;

FIG. 3 is an isometric illustration of the step-in binding embodiment of the present invention shown together with a boot;

FIG. 4 is an isometric illustration of the binding of FIG. 3 with the various parts thereof shown in the positions which they assume when the binding is in its unlatched position;

FIG. 5 is a sectional view of the binding of FIG. 4;

FIG. 6 is a plan view of the step-in binding of FIG. 3;

FIG. 7 is a side view of the binding of FIG. 6; and

Patented Dec. 12, 1967 FIGS. 8, 9, and 11. are isometric illustrations of the various individual components which combine to form the magnetic latching mechanism of the binding of the present invention.

Referring now to FIGS. 1 and 2, a ski 11 is equipped with a safety binding comprising a cable means 12, a magnetic latching means 13 and a toe locator 14. Cable means 12 includes a conventional ski binding cable 17 attached to the ski by means of cable guides 18 which prevent the cable from falling off of the ski while allowing the cable to move longitudinally along the ski. The guides 18 are disposed along the side edges of the ski 'at locations, relative to toe locator 14, which position the cable for urging the boot downwardly so as to prevent the boot heel from lifting off of the ski.

To secure boot 16 to ski 11 the latching mechanism 13 is released and the cable 17 is urged against the heel of the boot 16 and the latching mechanism 13 closed drawing the cable 17 taut with a force which has been preselected to suit the particular skier.

When a skier falls, a force is applied through the boot to the securing cable which directs the force to the latching mechanism. The force applied against the cable due to a fall exceeds any force applied against the cable during normal skiing conditions. Thus by adjusting the latching mechanism to open when normal skiing forces on the cable are exceeded, the binding is made to release the boot when the skier falls but hold the boot securely to the ski during normal skiing. Since the normal skiing forces applied against the cable vary with the weight and skiing experience of each individual skier, the release force of a ski binding must be variable to operate properly for different skiers.

The toe locator 14 performs several functions. It locates the boot on the ski relative to cable 17 to insure that the boot is secured to the ski with the same force each time the binding is operated. It acts as a reaction member to prevent the horizontal component of the force applied against the boot by the cable from changing the location of the boot on the ski. And it also acts as a temporary binding to assist in putting on skis.

The toe locating mechanism 14 (see FIGS. 6 and 7) includes an aluminum (or other non-magnetic material) mounting bracket 21 secured to the ski as by screws 22. The bracket 21 forms a generally cylindrical bore into which a generally helical spring 23 is disposed and retained by means of a screw 24. Secured within one end of the spring 23 by a press fit is a cylindrical magnetic pole piece 25. Secured Within the interior of pole piece 25 by screw 27 is a toroidal permanent magnet 26. The abutting relationship between the magnet 26 and the pole piece 25 operates to magnetize the pole piece and give it a magnetic polarity which is the same as the polarity of the face of magnet 26 which it contacts. A concave pole piece 28 is secured to the other face of magnet 26 by screw 27 and like pole piece 24 assumes a magnetic polarity consistent With the face of the magnet to which it is secured. The concave pole piece 28 is physically disposed within pole piece 25 but carefully arranged to be spaced a fixed distance from the interior defining boundaries thereof to avoid any contact between the two pole pieces. Thus since each pole piece is physically disposed from one another and each contacts an opposite face of the magnet 26 the pole pieces assume opposite polarities. The particular arrangement and shape of components set out above and shown in FIG. 7 results in magnetic pole pieces of opposite polarities having faces which are disposed in close relationship to one another so as to establish a path for efficient flux linkage therebetween. The magnet 26 and pole pieces 25 and 28 thus constitute a magnetic circuit which directs flux from one face of magnet 26 to pole piece 25, from pole piece 25 to pole piece 28 (through a small air gap), and through pole piece 28 to the opposite face of magnet 26.

Secured to the toe of boot 16 is a hemispherical toe keeper 29 formed from a magnetic material. The radius of keeper 29 is matched to the radius of pole piece 28 and the radius of pole piece 25 so that when toe keeper 29 is inserted into the locator 14 it contacts both pole piece 25 and pole piece 28 and thereby operates to magnetically short-circuit the flux path therebetween. This results in the toe keeper being magnetically held to the locator 14. The force with which keeper 29 is retained in locator 14 is a function of the size and strength of magnet 26 and the efficiency of flux linkage between the pole pieces 25 and 28. The toe locator 14 thus provides more than a locator and reaction member as described above. The force with which the toe keeper 29 is held to the locator is sufiicient to form a temporary binding between the boot and ski which is of great assistance when rebinding a ski under adverse conditions such as on a ski slope.

The gap between pole piece 25 and pole piece 28 is advantageously filled with a non-magnetic material such as epoxy.

For the foregoing description of the locator 14 it is clear that the toe locator can be advantageously employed with a wide variety of ski bindings and is not limited to use with magnetic bindings alone.

When a skier falls and his toe tends to disengage the locator 14, the spherical configuration of the locator and toe keeper cause the pole piece 25 to roll away from keeper 29 whereby the toe of the boot is released. In this way the binding responds to all forces caused by a fall regardless of the direction or type of fall to release the boot.

The screw 24 has three possible locations which enables the resilience of the toe piece to be adjusted. The resilience provided by spring 23 determines the force required to produce sufiicient movement between keeper 29 and pole piece 25 to result in disengagement and thus release of the boot toe. Thus by proper placement of screw 24 the toe locator can be made to properly suit a particular skier.

Referring now to FIGS. 3 and 4, a ski 31 is equipped with a step-in safety binding comprising a heel engaging lever mechanism 32, a magnetic latching means 33 and a toe locator 34. The magnetic latching means 33 and toe locator 34 are essentially identical with the magnetic latching means 13 and toe locater 14 previously described with reference to FIGS. 1 and 2. The association of magnetic latching means 33 with the lever means 32 produces a step-in type binding whereas the association of the magnetic latching means 13 with the cable means 12 produces a cable binding. The construction and operation of the magnetic latching means however, is essentially identical in both cases and thus a detailed explan' ation of the operation of the magnetic latching means 33 will also serve as a detailed explanation of the operation of the magnetic latching means 13 as well.

The magnetic latching means 33 is comprised of five main components: a generally toroidal shaped magnet 41, a lower pole piece 42, an upper pole piece 43 with an integrally connected bracket portion 44, a keeper plate 46 and a clevis member 47 for connecting the magnetic latching means to the particular boot securing means being employed.

The lower pole piece 42 is most clearly illustrated in FIG. 10 and comprises a generally flat bottom portion 51 which engages the upper surface of the ski 31 and is secured thereto by screws or other appropriate means. Integrally connected to the flat bottom portion 51 is a generally vertical upstanding portion 52 having a generally horizontal upper surface 53 at which all of the magnetic flux is concentrated, as will be described in more detail below. The toroidal magnet 41 is secured to the bottom portion 51 of the pole piece 42 as by a screw 54 (see FIG. 7) and gives a magnetic polarity to the pole piece 42 which is the same as that of the face of the magnet 41 which contacts the bottom portion 51.

The upper hole piece 43, as best illustrated in FIG. 11, comprises a generally horizontal plate portion 56 which is integrally connected to a downwardly extending portion 57 which joins another generally horizontally extending portion 58 which forms a portion of the bracket member 44. The generally flat portion 56 has a forward edge 59 which is specifically designed to be spaced at a distance from the upstanding portion 53 of bottom pole piece 42 when the upper plate piece 43 is operatively disposed over the upper surface of the magnet 41. For proper operation the space between edge 59 and portion 52 should not exceed one inch. When the upper pole piece is operatively positioned onto magnet 41 it assumes the magnetic polarity of the upper surface of magnet 41 whereby the forward edge 59 of upper pole piece 43 and the upstanding portion 53 of lower pole piece 42 present magnetized members of opposite polarities within close proximity of one another. A flux path is thus established across the gap between these two pole pieces whereby the major portion of the flux produced by the magnet 41 is concentrated along the upper edge 53 of the upstanding portion 52 of lower pole piece 42. In order to prevent snow or ice from entering between the gap that separates the leading edge 59 of pole piece 43 and the upstanding portion 52.0f pole piece 42 a shim of non-magnetic material 61 is disposed between the two pole pieces. The upper surface 56 of upper pole piece 43 and the upper surface of shim 61 form an essentially continuous surface which abutts pole piece 42, and lies vertically below the surface 53 thereof. Since the distance between the upper surface of pole piece 43 and the surface 53 of pole piece 42 determines the gap which exists when the keeper 46 engages surface 53, it is necessary to keep this distance less than one inch.

The shim 61 thus operates to prevent snow, ice or other foreign material from Working its way between the pole pieces. In order for proper operation of the invention it is essential that the shim 61 be of non-magnetic material such as brass.

The bracket portion 44 of upper pole piece 43 includes a pair of upstanding ears 6-2 which are integrally connected to the generally horizontal portion 58 which is secured to the upper surface of the ski as by screws 63 (see FIG. 7). A hole 50 is formed in each of the ears 62 and serves together with a pin 60a to create a hinge for pivotally connecting the keeper plate 46 to the bracket portion 44 of the upper hole piece 43.

The keeper 46, which, best illustrated in FIG. 9, ineludes a generally flat horizontal portion 66 which is integrally connected to a bracket portion 67 which includes a pair of depending ears 68 which have holes 60 formed therein for receiving pin 60a joins the ears to the upstanding ears 62 of the bracket portion of the upper pole piece 43. When the bracket portion 67 of keeper plate 46 is pivotally connected to the bracket portion 44 of upper pole piece 43 the forward edge 69 of the keeper 46 extends beyond the upstanding portion 52 of the lower pole piece 42. Thus when the keeper 46 is rotated downwardly it engages the upper surface 53 of the upstanding portion 52 along some portion of the generally horizontal portion 66 near the leading edge 69 thereof (see FIG. 7). The portion of keeper plate 46 which overlaps the surface 53 provides a convenient place for securing the keeper and pulling it upwardly to unlatch the binding.

As previously mentioned, when the keeper plate 46 does not contact the sun-face 53 the flux path is generally across the gap between the two pole pieces. When the keeper plate 46 contacts the surface 53, however, the flux path is generally between the upper pole piece 43 and the keeper plate 46 across the narrow air gap therebetween and through the hinged connection which joins the two. Thus when the keeper plate 46 contacts the upper surface 53 of lower pole piece 42 there is a physical connection between two members of opposite polarity resulting in a magnetic force holding the two members together. It is this securing force which provides both the cable binding and step-in binding of the present invention with the force for holding a boot to the upper surface of a ski. It is important to recognize that the connection between keeper plate 46 and lower pole piece 42 differs from 6 a connection which relies on spring force in that there is no allowable play between the two members. When the binding is latched, the keeper plate 46 is secured to the lower pole piece and the ski boot is secured to the ski. When the force applied to the binding produced is sufficient to separate the keeper plate from the lower pole piece the separation which results is complete and the boot is free to leave the ski. There are only the two possible conditions: latched and unlatched. There are no stable intermediate positions such as exist in a binding which uses a spring as a holding force. Undesirable heel lift is thus virtually eliminated.

Since the actual holding force which can be obtained between the keeper 46 and the lower pole piece 42 cannot realistically approach the force required to maintain a boot on a ski during normal skiing operation it is necessary to provide a mechanical linkage system which mult-i plies the securing force provided by the magnet.

The mechanical linkage system for connecting the magnetic latching means to the boot engaging means includes a clevis member 47 (see FIG. 8) which is pivotally secured to the bracket portion 67 of the keeper 46 (see FIG. 5). As best seen in FIG. 9 the holes 60 which receive the pivot pin that joins the keeper 46 to the bracket 44 are vertically below the holes 70 which receive a pivot pin 70a that connects the clevis 47 to the keeper 46. This vertical displacement between the two pivot connections creates a moment arm which operates in a counter-clock wise direction when a force is applied to the clevis 47 in a direction away from the leading edge 69 of the keeper 43. When the force on the clevis 47 reaches a desired magnitude, the turning moment about the pivot pin 60a operates to rotate the keeper 46 upwardly and separate it from the pole piece 42, as shown in FIG. 5.

One of the factors which determines how much force must be applied to the clevis 47 before the keeper 46 breaks loose from the pole piece 42 is the angle of the clevis 47 when the keeper is in its latched position. When the angle of the clevis 47 above the horizontal is increased, theforce required to unlatch the magnetic latching means decreases. Thus by varying this angle it is possible to vary the break loose force of binding and thus adjust the binding precisely to meet the requirements of a specific skier.

The angle of clevis 47 operates to vary the force required to unlatch the binding by changing the angle of the force vector acting on the binding. As the force vector is positioned away from the horizontal the component of the vector acting to create the turning moment is decreased thus requiring a greater force to produce the moment necessary for break-loose.

In order to make the angle of clevis 47 adjustable a screw 71 is disposed through the bracket ortion 44 of upper pole piece 43 directly below the clevis 47. The end of the clevis rests on the head of the screw 71 and thus by adjusting the height of the screw it is possible to adjust the angle of the clevis .and thus the break loose force which must be applied'to the clevis in order to separate the keeper 46 from the pole piece 42.

Attempts prior to the present invention to provide an efiective magnetic ski binding have often fallen short due in part to the problems presented by extremely low temperatures. It has been observed that when certain magnets are exposed to low temperatures (in the neighborhood of -20 C.) they tend to lose theirholding force and become ineffective as a latching means. It is because of this very phenomena that some otherwise advantageous magnets (Barium Ferrite) have been discarded as being useful in conjunction with ski bindings.

The present invention enables Barium Ferrite magnets to be advantageously employed even in extremely cold weather conditions by the use of. an upper pole piece 43 which completely covers the upper surface of the magnet. As previously explained, the upper pole piece 43 operates to concentrate the flux between the small gap which exists between the upper pole piece and lower pole piece,

and under no conditions of the binding is the magnet 41 disposed in a magnet circuit which includes more than a very small air gap (less than one inch). Thus, while the present invention has been found to operate satisfac torily at normal skiing temperatures without the presence of an upper pole piece 43 it is by virtue of pole piece 43 that the binding operates under extremely low temperature conditions as well.

Besides the presence of an upper pole piece such as pole piece 43, it has also been found that certain relationships must exist between the surface areas of the magnet 41, the distance between pole pieces, and the area of the surface which contacts the keeper, if successful operation at a reasonable cost is to be achieved. Although the precise reasons why these particular relationships in fact are required are not fully understood it has been demonstrated that failure to maintain these relationships results in either an inoperable device, or an impractical device. It has been found that the total surface area of the poles of the magnet 41 (that is the total upper surface area and bottom surface area) must be greater than ten times the distance between the poles (the thickness of the magnet). It has also been found that the area of the surface 53 (that is the surface which contacts the keeper) should be less than one-tenth the total surface area of the poles of the magnet.

When the magnetic latching mechanism 13 is to be used to form a step-in binding, the clevis member 47 is connected to the lever means 32 by a connecting rod 76 (see FIGS. 47). The threaded end 85 of connecting rod 76 passes through a hole in the clevis member 47 and has a nut 77 secured thereto. The nut 77 is larger than the hole in the clevis 47 and is non-rotatably positioned within the clevis whereby the connecting rod 76 can be rotated without rotating the nut 77. This enables the position of nut 77 on rod 76 to be easily varied. The other end of connecting rod 76 passes through a notch in the downwardly extending portion 87 of the heel engaging clamp member 78 which forms a portion of the lever means 32. The end of rod 76 which passes through the notch 75 (see FIGS. 3 and 4) in clamp member 78 carries an enlarged head 79 which has a greater diameter than the width of the notch 75, thus preventing the connecting rod from being pulled through the notch. The clamp 78 is secured to a pivot pin 81 as by welds, and the ends of pivot pin 81 are rotatably secured in the upstanding side members 82 of bracket 83. The bracket 83 is fixably secured to the upper surface of the ski 31 by means of screws 84.

To secure a boot onto ski 31, the keeper 46 is raised to the position shown in FIG. 5. Leftward movement of clevis 47 results, and causes the shaft 76 to move leftwardly under the urging of a rubber cushioning member 86 which surrounds the shaft 76 between the clevis 47 and the clamp 78. As the shaft 76 moves leftwardly the cushion 86 contacts the downwardly projecting portion 87 of the clamp 78 causing it to rotate clockwise on the pivot pin 31. When the clamp 78 pivots in a clockwise direction the generally horizontally extending portion 88 moves upwardly enabling the heel 89 of a boot to be positioned therebelow. When the boot is so positioned, the keeper 46 is urged downwardly until it contacts the surface 53 of lower pole piece 42 as shown in FIG. 7. As previously discussed in detail, contact between keeper 46 and pole piece 42 results in a magnetic force maintaining the two members together and requiring a counter-acting force to separate them.

The cushion member 86 also operates to absorb the shock produced when the binding releases and thus prevents damage to the connecting members.

When the keeper 46 is rotated downwardly the clevis 47 moves rightwardly carrying with it the shaft 76. As the shaft 76 moves rightwardly the head 79 secured at one end thereof contacts the lower extending portion 87 f the clamp 78 and causes it to rotate in a counterclockwise direction which brings the generally horizontally extending portion 88 of the clamp down onto the heel 89 of the boot 16. This results in the heel being firmly secured to the ski, which is the desired result.

When the heel 89 of the boot attempts to move upwardly relative to ski 31 it applies a force to the clamp 78 which attempts to rotate the clamp in a clockwise direction, which results in a force being applied to the clevis 47 in a direction away from the edge 69 of the keeper 46. As previously discussed, this creates a moment about the pin 60a which attempts to separate the keeepr 46 from the pole piece 42. By the proper adjustment of the height of screw 71 the force experienced by the clamp 78 during normal skiing conditions will be insufficient to cause the latching mechanism 31 to unlatch and thus the ski and boot will remain integral. If a skier should fall, however, the force applied to the clamp 78 will exceed normal skiing forces and be sufficient to cause the latching mechanism 33 to unlatch and release the boot from the ski.

Since ski boots have heels 89 which are of various heights it is necessary to make the position of the horizontally extending portion 88 of clamp 78 variable for the latched condition of the latching mechanism 33. To achieve the desired relationship the shaft 76 is rotated in order to change its position relative to the nut 77 Referring to FIGS. 1 and 2, the latching mechanism 13 operates in conjunction with a cable 17 through a connecting rod 91 which is secured at one end to clevis 47 and at the other end to a cable guide 92 through which the cable 17 passes. When the keeper 43 is raised the shaft 91 moves leftwardly toward the boot 16 which results in a relaxation of the cable 17 which in turn allows the boot to leave the ski 11. When the keeper 43 is secured to the lower pole piece 42, however, the cable 17 is drawn taut and the heel of boot 16 is firmly secured to the ski 11. Under normal skiing conditions the forces which are directed to the shaft 91 through cable 17 will be insufficient to cause the separation of keeper 43 from pole piece 42 and thus the binding will remain latched and the boot retained on the ski. If a skier should fall, however, the cable 17 will transmit a force to the shaft 91 which exceeds normal skiing forces which will result in the keeper 43 being separated from the pole piece 42 with the resulting relaxation of the cable 17 and release of the boot 16.

While the particular materials employed to form the present invention are for the most part design considerations which do not form a portion of the present invention, it is imperative that the pole pieces and keeper plate be formed from a magnetic material, and that the magnet be of a material capable of sustained operation under the adverse conditions in which a ski is expected to be operated. It has been found that magnets of Barium Ferrite having the chemical composition BAO-6Fe O operate better than other magnets presently commercially available.

What is claimed is:

1. In a ski binding for securing a boot to a ski the combination comprising:

boot securing means affixed to the ski; and

magnetic latch means disposed entirely on the ski operatively associated with said boot securing means, said magnetic latch means comprising:

a permanent magnet; a lower pole piece of magnetic material secured to said magnet; a keeper plate of magnetic material; means mounting said keeper plate and said pole piece for relative movement therebetween whereby said pole piece and said keeper plate have one relative position in which they are in contact and are magnetically urged together, and another relative position in which they are spaced at a distance from one another; said "means mounting said keeper plate and said pole piece for relative movement includes a pivot connection between said keeper plate and the ski; and

said boot securing means and said magnetic latching means are operatively associated through connecting means joined to said pivotally mounted keeper plate.

2. In a ski binding for securing a boot to a ski the combination comprising:

boot securing means aflixed to the ski; and

magnetic latch means disposed entirely on the ski operatively associated with said boot securing means; said magnetic latch means comprising:

a permanent magnet;

a lower pole piece of magnetic material secured to said magnet;

a keeper plate of magnetic material connected to the ski and to the boot securing means;

means mounting said keeper plate and said pole piece for relative movement therebetween whereby said pole piece and said keeper plate have one relative position in which they are in contact and are magnetically urged together, and another relative position in which they are spaced at a distance from one another;

said pole piece is secured to the ski and includes an upstanding portion having an upper surface disposed to engage said keeper;

said permanent magnet is generally toroidal with its lower face engaging said pole piece, said magnet of such dimensions that no portion thereof extends above the upper surface of the upstanding portion of said pole piece whereby said keeper plate is prevented from contacting said magnet when said keeper plate and said pole piece are in the relative position in which said keeper plate and said pole piece contact.

3. The ski binding of claim 2 wherein;

said means mounting said keeper plate and said pole piece for relative movement includes a pivot connection between said keeper plate and the ski;

said boot securing means and said magnetic latching means are operatively associated through connecting means joined to said pivotally mounted keeper plate.

4. The ski binding of claim 3 wherein said connecting means comprises;

a clevis member pivotally secured at one of its ends to said keeper plate at a point above the pivot connection between said keeper plate and the ski;

a connecting rod connected at one of its ends to the other end of said clevis member and at its other end to said boot securing means; and

means for adjusting the angle which said clevis member assumes when said keeper plate and pole piece contact whereby the required unlatching force is varied.

5. The ski binding of claim 4 wherein;

said means for adjusting the angle of said clevis member includes a screw disposed below the other end of said clevis member wherein the height of said screw is adjustable.

6. The ski binding of claim 4 wherein said boot securing means comprises;

lever bracket means secured to the ski;

a boot heel engaging lever pivotally mounted on said bracket means and having a generally horizontally extending portion disposed above the boot heel and a generally vertically depending portion connected to said connecting rod.

7. The ski binding of claim 6 further comprising;

a generally resilient sleeve surrounding said connecting rod between said clevis member and said lever.

8. The ski binding of claim 7 wherein;

the length of the connecting rod between said lever and said clevis member is adjustable to enable boot heels of various heights to be properly accommodated.

9. The ski binding of claim 3 wherein;

said boot securing means includes a cable which is drawn taut when said keeper plate contacts said pole piece and is relaxed when said keeper plate is disposed at a distance from said pole piece.

10. The ski binding of claim 3 wherein;

said boot securing means includes a lever mechanism for engaging a boot heel and holding it to the ski.

11. The ski binding of claim 3 wherein;

the combined area of the two faces of said magnet,

in square inches, is no less than ten times the distance between the magnet faces, in inches.

12. The ski binding of claim 3 wherein;

the combined area of the two faces of said magnet is no less than ten times the area of the upper surface of the upstanding portion of said pole piece.

13. The ski binding of claim 3 further comprising;

an upper pole piece secured to and substantially covering the upper face of said magnet, said upper pole piece having one defining boundary disposed adjacent the upstanding portion of said lower pole piece at a distance therefrom wherein the distance between said lower pole piece and said upper pole piece is not greater than one inch.

14. The ski binding of claim 13 further comprising;

a shim of non-magnetic material disposed between the upstanding portion of said lower pole piece and said upper pole piece filling the gap therebetween.

15. The ski binding of claim 13 wherein;

said upper pole piece and said pivot connection between said keeper plate and said ski are integrally connected.

16. The ski binding of claim 3 further comprising;

a generally hemispherical toe keeper of magnetic material secured to the toe of the boot;

a locator mounted on said ski for receiving said toe keeper; and

a permanent magnet associated with said locator supplying a magnetic force for holding the keeper and locator together once they are contacted.

17. A boot toe locator and holder for use with a ski comprising in combination;

a bracket secured to the ski;

a generally cylindrical pole piece of magnetic material resiliently mounted to said bracket;

a permanent magnet disposed in said pole piece with one pole thereof contacting said pole piece whereby said pole piece assumes a magnetic polarity; and

a generally hemispherical toe keeper of magnetic material secured to the boot toe for contacting one end of said pole piece and being magnetically held thereto.

18. The boot toe locator and holder of claim 17 further comprising;

a second pole piece having one concave surface and one generally planar surface wherein the planar surface is secured to the pole of said magnet opposite to that pole secured to said cylindrical pole piece, said second pole piece spaced apart from said cylindrical pole piece and disposed to engage said toe keeper when said toe keeper is disposed to contact one end of said cylindrical pole piece.

19. A boot toe locator and holder for a ski comprising in combination;

a cylindrical pole piece of magnetic material secured to the ski;

a permanent magnet secured to said cylindrical pole piece at an interior location thereof whereby said pole piece assumes one polarity of said magnet;

a disc shaped pole piece having a concave surface, said disc shaped pole piece secured to said magnet with the concave surface thereof disposed at one end of said cylindrical pole piece, said disc shaped pole piece having a magnetic polarity opposite to that of said cylindrical pole piece; and

a generally hemispherical toe keeper of magnetic material secured to the boot toe for engaging the end of said cylindrical pole piece and the concave surface of said disc shaped pole piece.

References Cited UNITED STATES PATENTS Crowther 280-1135 Cronberger 317-159 Watrous 317-159 10 Stitt 317-159 FOREIGN PATENTS 9/ 195 8 France. 8/ 1946 Switzerland. 7/ 1961 Switzerland.

BENJAMIN HERSH, Primary Examiner.

MILTON L. SMITH, Examiner. 

1. IN A SKI BINDING FOR SECURING A BOOT TO A SKI THE COMBINATION COMPRISING: BOOT SECURING MEANS AFFIXED TO THE SKI; AND MAGNETIC LATCH MAENS DISPOSED ENTIRELY ON THE SKI OPERATIVELY ASSOCIATED WITH SAID BOOT SECURING MEANS, SAID MAGNETIC LATCH MEANS COMPRISING: A PERMEANENT MAGNET; A LOWER POLE PIECE OF MAGNETIC MATERIAL SECURED TO SAID MAGNET; A KEEPER PLATE OF MAGNETIC MATERIAL; MEANS MOUNTING SAID KEEPER PLATE AND SAID POLE PIECE FOR RELATIVE MOVEMENT THEREBETWEEN WHEREBY SAID POLE PIECE AND SAID KEEPER PLATE HAVE ONE RELATIVE POSITION IN WHICH THEY ARE IN CONTACT AND ARE MAGNETICALLY URGED TOGETHER, AND ANOTHER RELATIVE POSITION IN WHICH THEY ARE SPACED AT A DISTANCE FROM ONE ANOTHER; 